September 1, 2009

Why do we yawn? A relatively simple question, at least it appears to be. The only thing is that we don’t actually know for certain why we yawn. Though there are many speculations of why we yawn there is no hard evidence that really proves any theory right.

Many scientists do hypothesize that yawning is triggered by fatigue or simply being bored. The reason is because during these moments breathing is shallow and there is little oxygen being carried to the lungs. A yawn is used to bring a sudden, large intake of oxygen into your body, heightening alertness, increasing heart rate, expelling carbon dioxide in the lungs and bloodstream, and forcing oxygen to the brain. This restores normal breathing and ventilation to the lungs.

Scientists believe that the explanation of “contagious” yawning is simply due to the power of suggestion. However, there are still many things scientists do not understand about yawning. For example, scientists have no idea why those with lower brainstem damage or multiple sclerosis excessively yawn. Even more baffling is the question of why fetuses in the womb yawn. Why is this so baffling? Well if yawning has to do with intaking oxygen then why would a fetus that doesn’t use its lungs to intake oxygen need to yawn?

Still a simple question? Thought not. Perhaps not the most medically important thing to ever happen, but a very interesting question none the less, simply due to the fact that there really isn’t a lot known about something as seemingly simple as yawning. Something many of us do daily.